GAPD: a GPU-accelerated atom-based polychromatic diffraction simulation code

Abstract

GAPD, a graphics-processing-unit (GPU)-accelerated atom-based polychromatic diffraction simulation code for direct, kinematics-based, simulations of X-ray/electron diffraction of large-scale atomic systems with mono-/polychromatic beams and arbitrary plane detector geometries, is presented. This code implements GPU parallel computation via both real- and reciprocal-space decompositions. With GAPD, direct simulations are performed of the reciprocal lattice node of ultralarge systems (∼5 billion atoms) and diffraction patterns of single-crystal and polycrystalline configurations with mono- and polychromatic X-ray beams (including synchrotron undulator sources), and validation, benchmark and application cases are presented.

Transitioning from File-Based HPC Workflows to Streaming Data Pipelines with openPMD and ADIOS2

“…GAPD is an "atom-based polychromatic diffraction simulation code for direct, kinematics-based simulations of X-ray/electron diffraction of large-scale atomic systems with mono-/polychromatic beams and arbitrary plane detector geometries" [6]. As such, it falls into the category of typical analysis codes that may be run on the raw data produced by a simulation such as PIConGPU.…”

“…GAPD is coupled with PIConGPU and configured to calculate the SAXS (Smallangle X-ray scattering) pattern from the input stream with the kinematical method [6]. The X-ray energy/wavelength, detection geometry can be adjusted in the input file whose configuration for the following benchmarks is found in the supplementary material along with software versions and an example for a created scatter plot [22].…”